In a conventional sense amplifier used in dynamic random access memory (DRAM) and having bit lines pre-charged to half of the operation voltage VDD, the gate overdrive voltage during sensing is quite small, especially in the 28 nm and below semiconductor process technologies, which slows down the sensing speed. The gate overdrive voltage is commonly known as the voltage difference between the gate-to-source voltage (e.g., voltage VGS) and the threshold voltage (e.g., voltage Vt) of a transistor. In some approaches, without using ultra-low threshold voltage (ULVt) devices, sensing may not meet the specified speed requirement and/or may require extra masks, which increases manufacturing cost.
Like reference symbols in the various drawings indicate like elements.